Friday, March 24, 2017

At the liberty of the winds

On 13 March, Panther had flown as far north as she could before crossing the Gulf of Mexico. She hovered on the coast of the Yucatan Peninsula in Mexico, faced with strong headwinds produced by the same unseasonably late cold front the late Bullfrog encountered. We hoped she would wait for the winds to calm, as we are all too aware how profoundly weather can affect a migrating Swallow-tailed Kite’s journey across the Gulf. Panther crept east out over the sea, skirting the north coast of Cuba before briefly seeking refuge on a barrier island north of Corralillo, Cuba. After a day of rest, she resumed her journey and made what appears to be an attempt at reaching Florida, just 100 miles north of her. Thwarted by winds from yet another cold front, she careened northwest until stalling over open water on 18 March. Finally, able to direct her path towards land, Panther reached Bradenton, Florida on 19 March. Despite having spent nearly 5 days over the Gulf, she wasted no time, settling back on her nesting grounds on the Florida Panther National Wildlife Refuge on 20 March. 

Palmetto from South Carolina, our longest-tracked kite, covered a significant amount of ground since we saw her enter Nicaragua on 14 March. She has passed Lacombe and will be the next kite to make the Gulf crossing. Southeasterly winds will be increasing in strength over the next two days, but should calm by Sunday morning. We wish Palmetto the best of luck.

The last time we heard from Sawgrass, she was still in South America in a region where there are few cell-phone towers to which her transmitter can download her accumulated GPS data. We aren’t worried yet. We experienced the same lapse in communication when Panther went through this entire area, not receiving data from her until she came online in Panama after 38 days of radio silence.

Not far behind Palmetto is Lacombe, a male Swallow-tailed Kite tagged in 2015 by our colleague Jennifer Coulson in Louisiana. Last year, he, like most of our satellite-tracked birds, migrated through the Gulf earlier in March and caught a lucky break that took him straight north to familiar grounds of Louisiana (see his path in "Sublime Creatures of the Wind"). What will his route look like this year?

MIA is already paired up and working on a nest in the Miami area.  We are hopeful that all the northbound Swallow-tailed Kites, tagged and un-tagged, will be back soon on the breeding grounds and beginning another annual nesting cycle

Wednesday, March 22, 2017

When no news is bad news

We’ve come to grips with the fact that we are no longer getting satellite data from Bullfrog, a female Swallow-tailed Kite tagged in June 2015 in the Tampa Bay area of Florida.
On 8 March 2017, Bullfrog leapt out over the Gulf of Mexico from the northeastern tip of the Yucatan Peninsula just north of Cancun. At first, she traveled northward with a good tailwind, but a late-season cold front created forceful headwinds that quickly stalled any forward movement. On 10 March, west winds developed and Bullfrog quickly took up a downwind course toward Florida. She made rapid progress until the winds changed again, now from the north, while she was still 200 miles from Florida.  She flew at high speed for nearly another 200 miles – but southward! This leg took her almost to Cuba before she took the ever-changing winds westward to the tip of the Yucatan, from which she had departed 3 days before. We were relieved, at least, that Bullfrog was now within 25 miles of land, where she could rest before making another attempt to reach Florida.

However, our relief was short-lived.  Rather than going ashore, Bullfrog’s drive to reach home took her northwest, riding the wind back out into the Gulf of Mexico, until she was once again struggling with headwinds. At that point, over water more than 4 full days and nights, not even a strong tailwind could carry her to shore in time. Bullfrog’s last location was in the Gulf of Mexico, 270 miles from the closest land. Undoubtedly, many other Swallow-tailed Kites, and many thousands of birds of many other species – untagged and unnamed – met the same fate during this period.

Bullfrog’s situation was, unfortunately, not unique. As we have learned from the similar scenarios that have played out for other Swallow-tailed Kites we were tracking, these birds cannot stay aloft more than 4 days without drinking or eating. In every case, large, unseasonable cold fronts resulted in persistent strong northerly winds, keeping these trans-Gulf migrants from reaching land in time. In 2013, three of the 11 Swallow-tailed Kites we were tracking died while laboring northward over the Gulf of Mexico in a similar weather pattern.

We celebrate Bullfrog today and the wealth of knowledge she provided over the last two years. She fledged two broods of two chicks each – the most any female kite ever accomplishes – during this time, and showed us her unique pre-migration route and communal roost sites through south Florida, her travel routes and winter destination, and all the places, from disturbed and degraded habitats to well-managed protected areas, that posed threats or served as refuges to her along her way.  We are grateful to the Florida Aquarium and its friends and supporters, especially Glory Moore and the St. Petersburg Audubon Society, for providing the necessary funding for Bullfrog’s transmitter and tracking data; and to Microwave Telemetry and CLS America for the technology to “see” into the lives of these amazing birds as they annually traverse the western hemisphere. 

We also thank all of you who are reading this story for your enthusiastic interest, and for being concerned about the well-being of our planet and its wild inhabitants. We appreciate all you are doing, and all we hope you will consider doing, to ensure that our choices and actions do not further imperil the natural world.

Tuesday, March 14, 2017

Closing the gaps

We have never seen a Swallow-tailed Kite do what MIA just did to reach his nesting area. After watching him seek refuge on Cuba during strong mid-Gulf headwinds, only to embark on a startling trip west across the Gulf to Louisiana rather than flying the short distance back to his Miami nest site, we imagined he would at least travel over land the remainder of the way home. Instead, he took a risky shortcut, launching out over the Gulf once again at Apalachee Bay in Florida’s eastern panhandle. He continued parallel to the west coast of Florida for 300 miles before returning to land in Cape Coral and closing the last 100+ miles to Miami. Finally, he is home.

Bullfrog is making her way across the Gulf of Mexico. She has been pushing against strong headwinds produced by late-winter cold fronts.  We are anxiously waiting for her transmitter to turn back on with good news. 

The last time we checked in on Lacombe and Palmetto, both were crossing the Andes Mountains. Now they are sailing rapidly through Central America. Lacombe is in southern Nicaragua, 420 miles ahead of Palmetto, in Panama. 

Panther has made it to the Yucatan Peninsula in Mexico and is now on the cusp of crossing the Gulf. We hope she waits for favorable weather.

Only Sawgrass remains in South America, presumably stocking up on insects, snakes, lizards, and frogs where Brazil, Peru, and Colombia all join, and where most of our tracked kites linger on their way north. 

Friday, March 10, 2017

In the spotlight: MIA

When MIA reached Cuba after changing course to avoid headwinds over the Gulf, we assumed he would be on his Miami nest territory within hours of resuming his flight. We were wrong.  The winds improved a bit as he rested over land, from northwest to southeast, apparently encouraging him the evening of 6 March to head back out over the ocean. However, this meant that, instead of ending up in the Everglades within a few hours, he was carried west-northwestward, missing the Keys and winding up back over the Gulf. Fortunately, he had enough strength and just enough of a southerly component in the wind to reach the Delta National Wildlife Refuge on 6 March, where the Mississippi River empties into the Gulf of Mexico. MIA then turned northward, crossing Chandeleur Sound to find refuge in a small, wooded area near Biloxi, Mississippi. Watching this drama unfold makes it easy to understand why northbound migration is the most dangerous time of the year for the Swallow-tailed Kites that nest in the United States.

Watch MIA cross the Gulf of Mexico in this short video:

To increase the resolution of the video, click the gear icon and select 1080p (HD).

On 26 February, MIA was traveling through Nicaragua. Wasting no time in reaching the northeastern tip of the Yucatan Peninsula in Mexico, he immediately began to cross the Gulf of Mexico. Interrupted by strong headwinds, MIA veered east to Cuba, taking a pit-stop necessary to wait for favorable crossing weather. But then, the winds shifted, and favorable tailwinds enabled MIA to make it safely to Louisiana. The remainder of the journey will be over land with plenty of resources along the way. 

Tuesday, March 7, 2017

Two Sighs of Relief

We last heard from Panther on 26 January – nearly 40 days ago. The weeks went by and we remained hopeful, but the kites face challenges and risks on their winter and migration ranges.  To our great relief, we just received data from Panther as she is making her way northward through Panama.

MIA faced harsh headwinds this weekend as he attempted to cross the Gulf of Mexico - weather that could have resulted in his death.  We know that Swallow-tailed Kites can endure no more than 4 days of over-water flight before becoming unable to continue.  However, MIA veered east in time, with the help of a slight shift in wind direction, and found refuge on Cuba 95 miles east of Havana. The winds have calmed and shifted to southerly, providing a tailwind that will ensure an easy final leg of to Florida and an arrival close to home.

Lacombe is beginning to cross the Andes Mountains. We should soon see Palmetto and Sawgrass do the same as they steadily move northward.

Costa Rica and Nicaragua might have seemed a blur to Bullfrog, who flew over land from Panama to Honduras in only 4 days. She will reach the Yucatan Peninsula within a few days and become our second tagged kite to take on the risky trans-Gulf flight home. 

Sunday, March 5, 2017

This most dangerous time of year

It seems that traversing the Andes Mountains lights a fire in northbound Swallow-tailed Kites. In just 8 days after this daunting crossing in southwestern Colombia, South America, MIA covered over 1,600 miles, including a circuitous path through all of Central America and the length of Mexico’s Yucatan Peninsula.  He launched on 3 March from the region’s northeastern tip with a welcome tailwind and is now out over the Gulf of Mexico. However, northeast winds with gusts to 32 mph are forecast for the next 2 days. These powerful headwinds will pose a serious challenge to MIA’s passage. At the least, his path and hoped-for landfall will be very difficult to predict. We will keep you informed.

Bullfrog rested briefly after crossing the Andes, but has since covered Panama and is about to cross into Costa Rica.  

GPS-tracking data for six Swallow-tailed Kites showing their location as of 3/3/17.

Notice how quickly MIA and Bullfrog are now moving compared with the leisurely pace of the other swallow-tails we are tracking. Data from the last few weeks for the birds still in South America show a consistent pattern: remain in an area for a few days, travel northward a few hundred miles or less, and repeat. However, once they cross the Andes, they fly continuously each day until reaching the Gulf coast of the northeastern Yucatan Peninsula.

Lacombe, Palmetto, and Sawgrass have all edged northward toward their intersection with the Andes Mountains. Lacombe is currently in the Amazonian rainforest on the north end of Peru. Palmetto traveled roughly 400 miles since our previous blog and is now in Brazil, just west of where Lacombe had passed at that time. Sawgrass cruised into Bolivia over the same ground Palmetto had just traversed.  

Panther’s location depicted on the map was her last fix, which we received on 26 January 2017. She probably has been beyond cell-tower range since then. We are hoping to hear from her soon.